Thermionic device



Dec. 13, 1927. 1;652,497

H. M. RYDER THERMIONIC DEVICE Filed June 25, 1921 s Sheets-Sheet 1 WITNESSES: INVENTOR j j BY W Dec. 13, 1927.

1,652,497 H. M. RYDER THERMIONIC DEVICE Filed June 25 1921 s Sheets-Sheet 2 I INVENTOR Har/YM RYaer. BY

. TNESSES:

ATTORNEY Dec. 13, 1927.

H. M. RYDER THERMIONIC DEVICE Filed June 25, 1921 3 Sheets-Sheet 5 j Wl/T/NfESSES: v

Patented Dec. 13, 1927.

UNITED STATES 1,652,497 PATENT OFFICE.

HARRY M. RYDER, OF WILKINSIBURG, PENNSYLVANIA, ASSIGNOR '10 WESTINGHOUSE ELECTRIC & MANUFACTURIN COMPANY, A CORPORATION OF PENNSYLVANIA.

THERMIONIC DEVICE. I

Application filed. June 25, 1921.

My invention relates to evacuated electric devices and more especially to the construction and arrangement of the electrodes emlployed in such devices.

11 its broad aspect, the object of my invention is to provide an evacuated electric device whichshall be of unusual simplicity in design and ruggedness of construction and which shall be of a higher operating efliciency than has heretofore been possible in such devices.

More specifically, one object of my invention is to provide a vacuum tube embodying an arrangement of electrodes wherein a cy- 15 li'ndrical anode is disposed concentric with the axis of the tube and wherein aplurality of filaments are disposed in the lateral surface of a cylinder surrounding the anode and disposed in symmetrical relation thereto.

Another object of my invention is to provide a filament-supporting structure where by the filaments will always be maintained in the roper relation to the anode and to the wal s of the tube. 1 I

Still another object of my invention is to provide a filament-supportmg structure of such character that the filaments may be connected in parallel and fed from bus bars constituting parts of the filament-supporting structure.

A further object. of my invention is to provide means whereby the temperature of the filament supply conductors in the press may be reduced without lowering the filament-current input.

A still further object of my invention is to provide an external control electrode composed of a metallic gauze and disposed concentric with the axis of the tube.

According to my invention, I provide an elongated vacuum-tube device which includes afilament structure axially supportcd from one end of the tube and a cooperating anode symmetrically disposed with respect to the filament structure and supported from an opposite end of the tube. The fila ments are disposed as longitudinal elements of a cylinder which lies between the containingwalls of the tube and the anode and is symmetrically disposed with respect to both. -A control electrode, which is preferably composed of a metallic gauze, is so'disposed that its field of force is substantially parallel to the space-current path between the filaments and the cylindrical anode.

Serial No. 480,303.

but showing a modification in the filamentsupporting structureoand, in addition, means for preventing vibration of the free end of the anode.

Figs. 4 and 5 are sections on lines IV-IV and respectively, of Fig. 3, looking in the dlrectlon of the arrows.

Fig. 6 is a front elevational view of a vac-- uum-tube device which differs from that of Fig. 1 in the filament structure and in the arrangement of the supporting electrodes within the tube, and H Fig. 7 is a section on the line VII-VII of Fig. 6.

Referring to the form of my invention illustrated in Figs. 1 and 2, I have shown a complete evacuated electric device in theform of an elongated tube 1 which has a plurality of filaments 2 and a cooperating anode 3 disposed therein. An external electrode 4 preferably of metallic gauze is disposed immediately adjacent the containing walls of the tube 1 but not necessarily in contact therewith.

The filaments 2, which are disposed as longitudinal elements of a right circular cylinder the axis of which is concentric with that of the tube 1, are supported by a pair of rings or so-called filament busses 5 and 6. The rings 5 and 6 are composed of a conducting material so that the filaments 2 may be fed in parallel. The tension of the filaments 2 may be adjusted by means of springs '7. The rings 5 and 6 are supported by means bedded in a press 16 that is disposed in the end of the tube 1 which is opposite to that supporting the filament structure. The supporting conductor 15 extends through the press 16 to form a supply lead to the anode 3. The anode 3 is symmetrically disposed with respect to the filaments 9. and also with respect to the walls of the tube'l. The grid 4, which may be disposed either within or without the containing walls of the tube 1, is symmetrically disposed with respect to the tilamcuts 2 and also with respect to the anode 3.

Referring to Figs. 3, 4: and 5, the vacuumtube device shown differs from that of Figs. 1 and 2 in the filament structure and in the addition of means for preventing the vibra tion of the free end of the anode 3.

In the modification just. mentioned, the filaments are divided into two groups supported at one end by a central ring (3' and at the other end by oppositely disposed endriugs 5'. The end-rings 5 are also connected in parallel by the simporting conductors 8 which also function as current leads to the ends of the filaments 2 that are supported by the annular rings 5. The cen tral ring (3 is carried by sul'iporting conductors 11 and 12. One end of the anode 3 is sup orted by the arms 14 and 15, as in the embodiment shown in Fig. 1. The unsupported end of the anode 3 is prevented from vibrating by means of a pair of cross-arms 17 which are in contact with the inner surface of the anode 3. The cross-arms 17 are supported by means of a supporting rod 18 embedded in the press 13.

In Figs. 6 and 7 is shown a further modification of the filament structure and the arrangement of the filament and anode supports within the tube. In the modification just referred to, it will be noted that the ring 5 is supported by means of a supporting conductor 19 having laterally disposed eross members 20, opposite ends of which are rigidly secured to the ring 5". The supporting conductor 19 may be so disposed as to coincide with the axis of the tube and is supported by. and extends through the press 13. The filament-supporting ring 6" is carried by arms 11 and 12, as in Fig. l. The filament leads 11 and 19 may be conneeted to a base .21 of any approved design.

The anode 3. instead of being supported from an opposite end of the tube, as in the previous figures, is supported by rods 9.2 and 23 which are also embedded in the press 13. A lead 24 serves to connect the anode 3 with external circuits through a binding post 25.

One advantage of the structural arrangement of electrodes embodying my invention is the resulting simplicity in design, ease of construction and cheapness of manufacture which it aflords.

Another advantage of a vacuum-tube device embodying my invention is its high operating eflieiency when employed as an oscillator in any of the well known oscillator circuits. In the usual type of vacuuminbe. oscillator, the operating efficiency has heretofore been approximate] y fifty per cent. In the tube embodying my invention, however, I have been able to obtain a maximum operating etlieicncy ol eighty-eight per cent, with an average of seventy per cent. As just stated, these relatively high cllicieneics were obtained when employing my tube as an oscillator in well known oscillator systems.

The favorable ope 'ating characteristics of the tube as an amplifier or oscillator result from the arrangement of the grid-shaped cathode in the space between the anode and the externally disposed auxiliary, or control electrode, thus securing to the external electrode a strong electrostatic controlling action in the space between the cathode and the anode where the major part of the electron discharge takes place.

Still another advantage of my invention resides in the fact. that, by employing a plurality of electrical parallel supply eonductors for the filament, I am enabled to reduce. very materially, the working ten'iperature of the conductors where they pass through the press. The maintenance of the relatively low temperatures of the filament supply conductors in the press is of especial importance in high-vacuum tubes by reason of the fact that there is a tendency for the filament seal to leak when the filament couductors are unduly heated.

\Vhile I have described and illustrated several preferred embodiments of my invention, I do not wish to be rest ricted thcreto, but. I desire that only such restrictions shall be placed upon my invention as are set forth in the appended claims.

I claim as my invention:

1. An evacuated electric device having a plurality of filaments disposed in a cylim drical surface, a co-operating anode disposed substantially symmetrically with respect. to said cylindrical surface. said filaments being disposed between said anode and the containing walls of said device. and an c.\'- ternal control electrode composed ot a metal gauze disposed substantially concentric with the axis of said cylindrical surface.

2. In a vacuum tube, a plurality of rings. a plurality of filaments supported by said rings, conducting supports for one of said rings. conducting supports for said remainmg rings. said remaining rings being connected in parallel by said last-named con ducting supports.

In testimony whereof. I have hereunto subscribed my name this 14th day of June,

HARRY M. RYDER. 

